/*
 * Copyright (c) 2005, 2006, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * questions.
 */

package javax.lang.model.element;

/**
 * Represents a value of an annotation type element. A value is of one of the
 * following types:
 * <ul>
 * <li>a wrapper class (such as {@link Integer}) for a primitive type
 * <li> {@code String}
 * <li> {@code TypeMirror}
 * <li> {@code VariableElement} (representing an enum constant)
 * <li> {@code AnnotationMirror}
 * <li> {@code List<? extends AnnotationValue>} (representing the elements, in
 * declared order, if the value is an array)
 * </ul>
 * 
 * @author Joseph D. Darcy
 * @author Scott Seligman
 * @author Peter von der Ah&eacute;
 * @since 1.6
 */
public interface AnnotationValue {

	/**
	 * Returns the value.
	 * 
	 * @return the value
	 */
	Object getValue();

	/**
	 * Returns a string representation of this value. This is returned in a form
	 * suitable for representing this value in the source code of an annotation.
	 * 
	 * @return a string representation of this value
	 */
	String toString();

	/**
	 * Applies a visitor to this value.
	 * 
	 * @param <R>
	 *            the return type of the visitor's methods
	 * @param <P>
	 *            the type of the additional parameter to the visitor's methods
	 * @param v
	 *            the visitor operating on this value
	 * @param p
	 *            additional parameter to the visitor
	 * @return a visitor-specified result
	 */
	<R, P> R accept(AnnotationValueVisitor<R, P> v, P p);
}
